A Clockless Temperature-Compensated Nanowatt Analog Front-End for Wake-Up Radios Based on a Band-Pass Envelope Detector

• Published in: IEEE transactions on circuits and systems. I, Regular papers Regular papers, 2020-08, Vol.67 (8), p.2612-2624
• Main Authors: Elgani, Alessia M., Renzini, Francesco, Perilli, Luca, Franchi Scarselli, Eleonora, Gnudi, Antonio, Canegallo, Roberto, Ricotti, Giulio
• Format: Article
• Language: English
• Subjects: Baseband; Bit error rate; Capacitance; Envelope detection; envelope detector; Envelope detectors; Error analysis; LF noise; Logic gates; MOSFETs; OOK modulation; Oscillators; Power consumption; Power demand; Room temperature; Sensors; subthreshold operation; Topology; ultra-low-power; Wake-up radio (WUR)
• ISSN: 1549-8328; 1558-0806
• DOI: 10.1109/TCSI.2020.2987850

This paper presents an Analog Front-End for integrated Wake-Up Radios. The proposed Analog Front-End is composed of an envelope detector, a Schmitt trigger and a biasing block and has three distinctive features: i) clockless solution, which does not require an always-on oscillator; ii) an envelope detector with band-pass response which leads to smaller capacitance, thus easier integration, and low-frequency noise suppression; iii) temperature compensated biasing scheme. An active scheme for the detector is used based on MOSFETs operated in the subthreshold region with a self-biased topology. Advantages and drawbacks of the proposed architecture are analyzed. A prototype was fabricated in the STMicroelectronics 90-nm BCD technology. The overall power consumption, excluding the biasing block, is 36 nW at 1.2 V. A 10 −3 Bit Error Rate is measured with a 771-MHz, 2-kbit/s OOK modulated input signal with −46 dBm power at room temperature and at −20 °C, and with almost −43 dBm power at 60 °C.